That fuctions are implementation of OpenGIS for spatial data. I'm using it with MySQL 4.1.0-alfa.
Check this:
mysql> CREATE TABLE t1 (g POINT);
mysql> INSERT t1 SET g=PointFromWKB(Point(1,1));
mysql> INSERT t1 SET g=PointFromWKB(Point(0,0));
mysql> INSERT t1 SET g=PointFromWKB(Point(1,0))...